What is the main characteristic of the hand of benediction?

The main characteristic of the hand of benediction is indeed defined by the inability to flex the 2nd and 3rd digit metacarpophalangeal joints. This condition is primarily associated with a median nerve injury, which affects the muscles responsible for flexing the fingers. When the patient attempts to make a fist, the 2nd and 3rd digits remain extended while the 4th and 5th can flex normally, creating a hand posture reminiscent of a blessing or gesture of benediction.

This inability occurs because the flexor digitorum superficialis and profundus muscles, which flex these fingers, are no longer adequately innervated. The flexion of the 4th and 5th digits remains possible due to their innervation by the ulnar nerve, allowing those digits to flex normally.

Understanding this mechanism is critical for recognizing the clinical presentation associated with median nerve damage and distinguishing it from other potential hand conditions that may involve different digit movements, such as extension issues or thumb opposition problems.